Resilient sheet



March 5, 1940. 1.. A. DUNAJEFF RESILIENT SHEET Original Filed July 21,1938 Pic. 2

Izizi-zzzgg 2 Sheets-Sheet 1 .ZEO/V/D A. Du/vA JEFF INVENTOR.

BY M m,

ATTORNEY.

March 5, 1940; L. A. DUNAJEFF 2, RESILIENT 'SHEET Original Filed July21, 19:58 2 Sheets-Sheet 2 Eq: I ZEd/v/o A. DUN/4 JEFF INVENT OR.

BY 1m P- Maw ATTORNEY.

' Patented Mar. 5, 1940 znzsn rarsnr oFFicE RE'SILIENT SHEET Leonid A.Dnnajeff, New York, N. Y., assignor to Commercial IngredientsCorporation, New

York, N. Y.

Application July 21, 1938, Serial No. 220,489 Renewed December 28, 1939Claims.

My invention relates to resilient sheets and has particular reference tosheets resiliently expansive in lateral directions.

My invention has for its object to provide a 5;. sheet with a desireddegree of lateral stretchability under action of applied forces actingin the plane of the sheet or transversely thereto, in the latter casethe sheet being adapted to resiliently buckle if held by its edges. Forthis purpose I use a sheet preferably made of an inherently resilient orelastic material, such as steel or other suitable metal, Celluloid,fiber, rubber of a desired degree of hardness, molded composition, etc,and further increase the lateral flexibility or stretchability of thesheet by perforating it in such manner that portions between theperforations form zig-Zag shaped or curved bridges. The size andcurvature of these bridges is arranged so that the bridges can bedeflected or resiliently straightened out by the action of appliedforces, and they may be considered as corrugations in the plane of thesheet. The pattern of the perforations may be made uniform throughoutthe sheet in order to obtain uniform flexibility or resiliency in allits points, or the pattern may vary if it is desired to vary theresiliency at certain points of the sheet. The bridges are preferablymade to extend in different directions in order to render the sheetlaterally expansive in all directions. Such a sheet is characterized byits ability to stretch in all directions, increasing its area when sostretched.

When secured by its edges in a frame, the sheet will resiliently stretchunder action of forces transverse to the plane of the sheet, theelongation being obtained. from the straightening of the curves of thebridges.

My sheet can be made suiiiciently elastic so that it can be used forchair seats, mattresses, backs of seats, etc, and for other purposeswhere re. lient flexibility and stretchability may be required.

The corrugated bridges, to be resiliently flexible, must be narrow,their width being comparable or corresponding to the thickness of thematerial. The flexibility of the wide bridges can be increased bytransversely curving the edges of the bridges so as to form the bridgesinto channels open at one side of the sheet.

Certain typical forms and embodiments of my invention are described inthe accompanying specification, from which full understanding of myinvention and its operation can be had, and the invention is furtherdisclosed in the accompanying drawings in which Fig. l is a plan view ofmy sheet with elements connected by curved bridges.

Fig. 2 is an enlarged detail view of the same.

Fig. 3 is a side view of the same.

Fig. 4 is a plan View of a modified sheet with ring-shaped elements orportions connected by curved bridges.

Fig. 5 is an enlarged detail view of the same.

Fig. 6 is an end view of the same.

Fig. 7 is a plan View of another modification jio showing ringsconnected by bridges.

Fig. 8 is a detail view of the same.

Fig. 9 is an end view of the same.

Fig. 10 is another modification of ring-shaped elements connected bybridges.

Fig. 11 is an end view of the same.

Fig. 12 is a plan view of a sheet having elongated rings.

Fig. 13 is an end view of the same.

Fig. 14 is a diagrammatic View showing 0 stretching of a sheet similarto the sheet shown in Fig. 1.

Fig. 15 is a diagrammatic View showing stretching of a sheet similar tothe sheet shown in Fig. 7.

Fig. 16 is a diagrammatic view showing stretching of a sheet formed ofwire rings.

Fig. 17 is a fractional detail view of ringshaped portions and curvedbridges curved into open channels.

Fig. 18 is a sectional view taken on the line l8-l8 of Fig. 1'7.

My resilient sheet can be made in a variety of different forms, allthese forms being characterized by separate pieces or elements connectedtogether, preferably integrally, by bridges, the pieces and the bridgesbeing, for instance, formed or stamped out, their contours being definedby perforations. The sheet can be made of metal, fibrous or cellulosematerial, in which case the perforations may be stamped out in suitabledies; or, if made of a suitable metal, alloy or composition, the wholesheet may be cast or pressed out between rolls. If made of acomposition, the sheet may be formed in hot or cold dies. The resilientlateral flexibility or stretchability is obtained by giving the bridgesa curved or zig-zag shape, or by making the elements or piecesthemselves in the form of flexible rings. One example of such a sheet isshown in Figs. 1, 2 andS, Figs. 2 and 3 representing detail view'of thesheet on an enlarged scale. The sheet l is provided with perforations 2of such a shape that square pieces 3 are formed connected to-' gether attheir corners by bridges 4. The bridges CAD are curved in the plane ofthe sheet as shown and can, therefore, resiliently stretch or straightenout when a force or forces are applied to the sheet. The material of thesheet must, of course, be resiliently flein'ble. The curvature must besufiicient to bring the middle portion of the bridge entirely outside ofa straight line passing through its ends; in other words, there shouldnot be any uninterrupted straight line of material between the ends ofthe bridge.

The effect of lateral forces on a sheet of a pattern somewhat similar tothe pattern of the sheet 8 is shown in Fig. 1.4. The bridges 4' can bestretched by straightening out their curvature as shown in dotted lines,with the result that the elements A, B, C and D will move outwardly indifferent directions into new positions A, B, C and D. The area ABCDwill then expand into the area A'BCD.

Pieces or elements between the bridges can be also made resilientlyyieldable by forming them in the shape of flexible rings 5 as shown inFigs. 4, 5 and 6, Figs. 5 and 6 being detail view of the elements andbridges. With a sheet formed as shown, not only the bridges 4 willresiliently stretch under action of applied forces, but the ringsthemselves will be resiliently deformed, the curved sides beingstraightened out in direction of stresses produced by the forces.

Modified forms of my sheet with bridged flexible rings are shown inFigs. 7, 8, 9, 10 and 15, Figs. 8, 9, 10 and 15 representing enlargeddetail views of the bridged elements. Such a sheet can be stretched inall directions or, if fastened rigidly at its edges in a frame, can beresiliently depressed by the application of a force transverse to theplane of the sheet. The arcuate portions I between the bridges will bestraightened out, tending to form straight lines, so that the rings willtend to be stretched out into squares or rectangles, as shown in dottedlines in Fig. 15.

The sheet as shown in Fig. 15 will expand in all directions, enlargingits area, when the points A will move outwardly into new positions A.This effect is also shown diagrammatically in Fig. 16 where wire rings 9are joined by clips ID. The rings when subjected to the stretchingaction, will tend to become straightened out so as to form squares asshown in dotted lines.

The elements between the bridges may be made elongated as shown in Figs.12 and 13, the sheet in this case being formed of a plurality ofelongated rings 8 joined together at their outer end portions.

In order to impart greater flexibility to any of the described forms ofelements and bridges, the sides of the rings and the bridges may bemodified by bending their edges into channels, for instance, of aU-shaped section. A detail view of such a modification is shown in Figs.17 and 18. The expanded structure is shown in dotted lines, the U-shapedbridge expanding in certain portions, particularly at the bends, andcollapsing at other portions, especially between the bends. The width Aexpands into A.

Other similar. modifications can be formed! with my invention, the onlynecessary requirement being that the sheet should be of an inherentlyresilient or elastic material and the perforations should be made sothat the sheet should have a plurality of curved or zig-zag shapedbridges or ring-shaped portions, extending in different directions sothat they can resiliently expand or deform under action of appliedforces.

I claim as my invention:

1. A resilient sheet made of a resilient material having elementsseparated by perforations, the elements being of a relatively narrowwidth comparable to the thickness of the sheet and curved edgewise inthe plane of the sheet, the curvature being wholly imparted by theperforations and being such as to bring the middle portion of eachelement entirely outside of any straight line passing through its ends,the element being thereby adapted to substantially straighten out understress and to increase the distance between its ends, the elementsextending in different directions thereby rendering the sheet expansivesimultaneously in all directions.

2. A resilient sheet made of a resilient material having elements of anapproximately arcuate shape of a narrow width comparable to thethickness of the sheet, the elements being wholly formed by perforationsand having curvature in the plane of the sheet, the middle portion ofeach element extending wholly outside of any straight line passingthrough its ends, the element being thereby adapted to straighten outits curvature under stress and to increase the distance between itsends, the elements thereby rendering the sheet laterally expansivesimultaneously in all directions.

3. A resilient sheet made of a hard resilient material and so perforatedas to form portions connected together by relatively narrow bridgescurved edgewise in the plane of the sheet, the middle portion of eachelement extending wholly outside of any straight line passing throughits ends, the element being thereby adapted to substantially straightenout under stress and to increase the distance between its ends, theelements extending in different directions thereby rendering the sheetexpansive simultaneously in all directions.

4. A resilient sheet made of a resilient material so perforated as toform ring-shaped elements connected by bridges, the arcuate portionsbetween the bridges being relatively narrow in comparison to their widthand being curved entirely in the plane of the sheet, the inner edge ofthe arcuate portion extending entirely outside of any straight linepassing through the ends of the portion, the portion being therebyadapted to substantially straighten out under stress and to increase thedistance between its ends, the elements extending in differentdirections thereby rendering the sheet expansive simultaneously in alldirections.

5. A resilient sheet made of a resilient material so perforated as toform ring-shaped elements connected together at diiferent points,portions of rings between the points of connection forming arc-shapedbridges curved in the plane of the sheet, the middle portion of eachbridge extending outside of any straight line passing through the endsof the bridge, the bridge being thereby adapted to straighten out and tolengthen between the end points, the sheet being there by renderedstretchable simultaneously in all directions.

LEONID A. DUNAJEFF.

